Question

The speed of a molecule of gas in a cubical vessel of side 5m is 15 ms${}^{-1}$. This molecule is constantly colliding with the walls of the container. The collision frequency will be

• A. 0.2 per second
• B. 1.5 per second
• C. 2.5 per second
• D. 5 per second

Answer 1

The correct option is B 1.5 per second

Given speed of the gas molecule $=15m/s$

Side of the cubical vessel $=5m$

Therefore, between two collision from the same wall distance travelled $=2\times 5=10m$

$T$ between succesive collisions $=10/15$

Frequency $=15/10=1.5$ persec